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  "description": "The Open Container Initiative (OCI) is an open governance body, hosted by the Linux Foundation, that maintains the standard specifications for container images, runtimes, and distribution. OCI specs are why a container built with one tool runs on another, and why Docker, Podman, Kubernetes, and cloud platforms can interoperate.\n\n\nThe three specs\n\n * Image Specification. Defines the on-disk format of a container image: manifests, layers as tar archives, content-addressable digests.\n * Runtime Spe",
  "path": "/engineering-glossary/oci-open-container-initiative/",
  "publishedAt": "2026-05-12T18:40:34.000Z",
  "site": "https://sahilkapoor.com",
  "tags": [
    "Docker",
    "Kubernetes",
    "containerd",
    "Container Runtime",
    "Image Layer"
  ],
  "textContent": "**The Open Container Initiative (OCI)** is an open governance body, hosted by the Linux Foundation, that maintains the standard specifications for container images, runtimes, and distribution. OCI specs are why a container built with one tool runs on another, and why Docker, Podman, Kubernetes, and cloud platforms can interoperate.\n\n## The three specs\n\n  * **Image Specification.** Defines the on-disk format of a container image: manifests, layers as tar archives, content-addressable digests.\n  * **Runtime Specification.** Defines how a runtime should launch a container from a filesystem bundle and a config (Linux namespaces, cgroups, mount points, capabilities).\n  * **Distribution Specification.** Defines the registry API for pushing and pulling images, used by Docker Hub, GHCR, ECR, GAR, ACR, Harbor, Artifactory.\n\n\n\n## Reference implementations\n\n  * **runc.** Reference OCI runtime, originally from Docker; used by containerd, CRI-O, and most others under the hood.\n  * **umoci, skopeo.** Image manipulation and registry interaction tools.\n  * **distribution / Docker Registry.** Reference implementation of the distribution spec.\n\n\n\n🔗\n\n**Related Terms**\nDocker, Kubernetes, containerd, Container Runtime, Image Layer.",
  "title": "OCI",
  "updatedAt": "2026-05-13T19:14:47.344Z"
}